I'm so sorry you went through that, I can't imagine the hurt you must be feeling. It's difficult to imagine someone as shamelessly malicious as that, it's just bizarre. He called you unattractive but he is really repulsive. Please try to realise that you were just really unlucky to meet someone as uncommonly disgusting as him. You're certainly not stupid, it would've happened to anyone, it'd be paranoid of you to suspect everyone you meet to be a complete psychopath.
You should indeed talk to someone to let it all out. But then after that you should try to look on the bright side and not let it consume you. You've gotten your heart broken in the worst possible way, once you overcome this you'll be incredibly strong as a result. Plus there are plenty of really good guys out there just waiting to meet someone like you, in the future you'll meet the one that just completes you and you'll have long forgotten about this loser.